Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2017 | Nov. 07, 2017 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2017 | |
Document Fiscal Year Focus | 2,017 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | LIFE | |
Entity Registrant Name | aTYR PHARMA INC | |
Entity Central Index Key | 1,339,970 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Smaller Reporting Company | |
Entity Common Stock, Shares Outstanding | 29,758,347 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016 |
Current assets: | ||
Cash and cash equivalents | $ 29,765 | $ 38,388 |
Available-for-sale investments, short-term | 60,616 | 33,759 |
Prepaid expenses and other assets | 1,825 | 2,621 |
Total current assets | 92,206 | 74,768 |
Available-for-sale investments, long-term | 4,002 | |
Property and equipment, net | 2,191 | 1,421 |
Other assets | 90 | 333 |
Total assets | 94,487 | 80,524 |
Current liabilities: | ||
Accounts payable | 3,592 | 2,606 |
Accrued expenses | 3,861 | 5,450 |
Current portion of deferred rent | 130 | |
Current portion of long-term debt, net of issuance costs | 2,267 | 339 |
Total current liabilities | 9,720 | 8,525 |
Long-term debt, net of current portion and issuance costs | 12,479 | 9,198 |
Commitments and contingencies (Note 3) | ||
Stockholders’ equity: | ||
Preferred stock, $0.001 par value; authorized shares – 5,000,000 at September 30, 2017 and December 31, 2016; Class X Convertible Preferred Stock issued and outstanding shares– 2,285,952 and no shares at September 30, 2017 and December 31, 2016, respectively | 2 | |
Common stock, $0.001 par value; authorized shares – 150,000,000 as of September 30, 2017 and December 31, 2016; issued and outstanding shares – 29,715,798 and 23,744,832 as of September 30, 2017 and December 31, 2016, respectively | 30 | 24 |
Additional paid-in capital | 325,031 | 278,832 |
Accumulated other comprehensive loss | (63) | (76) |
Accumulated deficit | (252,712) | (215,979) |
Total stockholders’ equity | 72,288 | 62,801 |
Total liabilities and stockholders’ equity | $ 94,487 | $ 80,524 |
Condensed Consolidated Balance3
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2017 | Dec. 31, 2016 |
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 5,000,000 | 5,000,000 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 150,000,000 | 150,000,000 |
Common stock, shares issued | 29,715,798 | 23,744,832 |
Common stock, shares outstanding | 29,715,798 | 23,744,832 |
Class X Convertible Preferred Stock [Member] | ||
Preferred stock, shares issued | 2,285,952 | 0 |
Preferred stock, shares outstanding | 2,285,952 | 0 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Operating expenses: | ||||
Research and development | $ 7,133 | $ 10,395 | $ 24,757 | $ 33,702 |
General and administrative | 3,694 | 3,470 | 11,188 | 11,711 |
Total operating expenses | 10,827 | 13,865 | 35,945 | 45,413 |
Loss from operations | (10,827) | (13,865) | (35,945) | (45,413) |
Other income (expense), net | (363) | 46 | (788) | 124 |
Net loss | $ (11,190) | $ (13,819) | $ (36,733) | $ (45,289) |
Net loss per share, basic and diluted | $ (0.43) | $ (0.58) | $ (1.50) | $ (1.91) |
Weighted average common shares outstanding, basic and diluted | 25,818,008 | 23,696,511 | 24,462,835 | 23,669,154 |
Condensed Consolidated Stateme5
Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Statement Of Income And Comprehensive Income [Abstract] | ||||
Net loss | $ (11,190) | $ (13,819) | $ (36,733) | $ (45,289) |
Other comprehensive gain (loss): | ||||
Change in unrealized gain (loss) on available for sale investments, net of tax | (6) | (12) | 13 | 178 |
Comprehensive loss | $ (11,196) | $ (13,831) | $ (36,720) | $ (45,111) |
Condensed Consolidated Stateme6
Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2017 | Sep. 30, 2016 | |
Cash flows from operating activities: | ||
Net loss | $ (36,733) | $ (45,289) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation and amortization | 552 | 679 |
Stock-based compensation | 3,649 | 3,877 |
Accretion of debt discount | 133 | 130 |
Amortization of premium of available-for-sale investment securities | 113 | 496 |
Deferred rent | (130) | (234) |
Changes in operating assets and liabilities | ||
Prepaid expenses and other assets | 802 | (937) |
Accounts payable and accrued expenses | (444) | 112 |
Net cash used in operating activities | (32,058) | (41,166) |
Cash flows from investing activities: | ||
Purchases of property and equipment | (1,152) | (554) |
Purchases of available-for-sale investment securities | (65,302) | (26,244) |
Maturities of available-for-sale investment securities | 42,347 | 51,723 |
Net cash (used in) provided by investing activities | (24,107) | 24,925 |
Cash flows from financing activities: | ||
Proceeds from issuance of common stock through option exercises | 37 | 20 |
Proceeds through employee stock purchase plan | 88 | 75 |
Proceeds from borrowing, net | 4,930 | |
Proceeds from issuance of securities of Private Placement, net of issuance cost | 42,487 | |
Repayments on loans payable | (2,547) | |
Net cash provided by (used in) financing activities | 47,542 | (2,452) |
Net change in cash and cash equivalents | (8,623) | (18,693) |
Cash and cash equivalents at beginning of period | 38,388 | 53,025 |
Cash and cash equivalents at the end of period | 29,765 | $ 34,332 |
Supplemental schedule of noncash investing and financing activities: | ||
Private Placement issuance costs included in accounts payable and accrued expenses | $ 90 |
Organization, Business, Basis o
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2017 | |
Accounting Policies [Abstract] | |
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies | 1. Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies Organization and Business aTyr Pharma, Inc. (we, us, and our) was incorporated in the state of Delaware on September 8, 2005. We are focused on the discovery and clinical development of innovative medicines for patients suffering from severe rare diseases. Principles of Consolidation Our consolidated financial statements include our accounts and our 98% majority-owned subsidiary in Hong Kong, Pangu BioPharma Limited (Pangu BioPharma). All intercompany transactions and balances are eliminated in consolidation. Unaudited Interim Financial Information The accompanying interim condensed consolidated financial statements are unaudited. These unaudited interim financial statements have been prepared in accordance with United States generally accepted accounting principles (GAAP) and following the requirements of the United States Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. In our opinion, the unaudited interim financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of our financial position and our results of operations and cash flows for periods presented. These statements do not include all disclosures required by GAAP and should be read in conjunction with our financial statements and accompanying notes for the fiscal year ended December 31, 2016, contained in our Annual Report on Form 10-K filed with the SEC on March 16, 2017. The results of the interim periods are not necessarily indicative of the results expected for the full fiscal year or any other interim period or any future year or period. Liquidity and Financial Condition We have incurred losses and negative cash flows from operations since our inception. As of September 30, 2017, we had an accumulated deficit of $252.7 million and we expect to continue to incur net losses for the foreseeable future. We believe that our existing cash, cash equivalents and available-for-sale investments, of $90.4 million as of September 30, 2017 will be sufficient to meet our anticipated cash requirements for at least a period of one year from the filing date of this Quarterly Report. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which we expect will take a number of years at a minimum. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, we will need to raise substantial additional capital. The amount and timing of our future funding requirements will depend on many factors, including the pace and results of our preclinical and clinical development efforts and the timing and nature of the regulatory approval process for our product candidates. We anticipate that we will seek to fund our operations through public or private equity or debt financings, collaborations, strategic partnerships or other sources. However, we may be unable to raise additional capital or enter into such other arrangements when needed on favorable terms or at all. If we are unable to obtain funding on a timely basis, we may be required to significantly curtail, delay or discontinue one or more of our research or development programs or the commercialization of any product candidates, or we may be unable to expand our operations, maintain our current organization and employee base or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition and results of operations. Use of Estimates Our consolidated financial statements are prepared in accordance with GAAP. The preparation of our consolidated financial statements requires us to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in our consolidated financial statements and accompanying notes. The most significant estimates in our consolidated financial statements relate to the fair value of equity issuances and awards, and clinical trials and research and development expense accruals. Although these estimates are based on our knowledge of current events and actions we may undertake in the future, actual results may ultimately differ materially from these estimates and assumptions. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents and adjusted for the weighted average number of common shares outstanding that are subject to repurchase. We have excluded 175 and 21,871 shares subject to repurchase from the weighted average number of common shares outstanding for the three months ended September 30, 2017 and 2016, respectively. We have excluded 4,607 and 29,467 shares subject to repurchase from the weighted average number of common shares outstanding for the nine months ended September 30, 2017 and 2016, respectively. Diluted net loss per share is calculated by dividing the net loss by the weighted average number of common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for common stock, restricted stock units and options outstanding under our stock option plan and employee stock purchase plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to our net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Three and Nine Months Ended September 30, 2017 2016 Class X Convertible Preferred Stock (if-converted) 11,429,760 — Warrants for common stock 6,642,332 25,970 Common stock options and restricted stock units 4,745,715 4,356,751 Employee stock purchase plan 38,862 37,944 22,856,669 4,420,665 Convertible Preferred Stock We apply the relevant accounting standards to distinguish liabilities from equity when assessing the classification and measurement of preferred stock. Preferred shares subject to mandatory redemptions are considered liabilities and measured at fair value. Conditionally redeemable preferred shares are considered temporary equity. All other preferred shares are considered as stockholders’ equity. Derivative Financial Instruments We do not use derivative instruments to hedge exposures to cash flow, market, or foreign currency risks. We evaluate all of our financial instruments, including warrants, to determine if such instruments are derivatives or contain features that qualify as embedded derivatives. We generally use the Black-Scholes option-pricing model to value the derivative instruments at inception and subsequent valuation dates. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is re-assessed at the end of each reporting period. Recent Accounting Pronouncements In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities , which requires that (i) all equity investments, other than equity-method investments, in unconsolidated entities generally be measured at fair value through earnings and (ii) when the fair value option has been elected for financial liabilities, changes in fair value due to instrument-specific credit risk will be recognized separately in other comprehensive income. Additionally, ASU 2016-01 changes the disclosure requirements for financial instruments. The new standard will be effective for fiscal years beginning after December 15, 2017, and interim periods within those annual fiscal years. Early adoption is permitted for certain provisions. The adoption of ASU 2016-01 is not expected to have a material impact on our consolidated financial position or results of operations. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In May 2017, the FASB issued ASU 2017-09 , Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting, |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2017 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 2. Fair Value Measurements The carrying amounts of cash equivalents, prepaid and other assets, accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates currently available to us for loans with similar terms, which is considered a Level 2 input, we believe that the carrying value of our Term Loans approximates its fair value. Investment securities are recorded at fair value. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Financial assets measured at fair value on a recurring basis consist of investment securities. Investment securities are recorded at fair value, defined as the exit price in the principal market in which we would transact, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Level 2 securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data, or discounted cash flow techniques and include our investments in corporate debt securities and commercial paper. We have no financial liabilities measured at fair value on a recurring basis. None of our non-financial assets and liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented. Assets measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Quoted Active for Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2017: Assets: Current: Cash equivalents $ 17,907 $ 17,907 $ — $ — Available-for-sale investments, short-term: Asset-backed securities 7,402 — 7,402 — Commercial paper 21,193 — 21,193 — Corporate debt securities 21,594 — 21,594 — United States treasury securities 10,427 10,427 — Sub-total short-term investments 60,616 10,427 50,189 — Total assets measured at fair value $ 78,523 $ 28,334 $ 50,189 $ — As of December 31, 2016: Assets: Current: Cash equivalents $ 29,251 $ 29,251 $ — $ — Available-for-sale investments, short-term: Commercial paper 7,843 — 7,843 — Corporate debt securities 20,913 — 20,913 — United States treasury securities 5,003 5,003 — — Sub-total short-term investments 33,759 5,003 28,756 — Available-for-sale investments, long-term: Asset-backed securities 4,002 — 4,002 — Sub-total long-term investments 4,002 — 4,002 — Total assets measured at fair value $ 67,012 $ 34,254 $ 32,758 $ — As of September 30, 2017 and December 31, 2016 available-for-sale investments are detailed as follows (in thousands): September 30, 2017 Gross Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Market Value Available-for-sale investments, short-term: Asset-backed securities $ 7,403 — (1 ) $ 7,402 Commercial paper 21,193 — — 21,193 Corporate debt securities 21,601 — (7 ) 21,594 United States treasury securities 10,433 — (6 ) 10,427 $ 60,630 $ — $ (14 ) $ 60,616 December 31, 2016 Gross Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Market Value Available-for-sale investments, short-term: Commercial paper $ 7,843 $ — $ — $ 7,843 Corporate debt securities 20,942 — (29 ) 20,913 United States Treasury securities 5,002 1 — 5,003 $ 33,787 $ 1 $ (29 ) $ 33,759 Available-for-sale investments, long-term: Asset-backed securities $ 4,001 $ 1 $ — $ 4,002 $ 4,001 $ 1 $ — $ 4,002 As of September 30, 2017, all of our available-for-sale investments have effective maturity dates of less than one year. As of September 30, 2017, there are 18 available-for-sale investments in a gross unrealized loss position, all of which had been in such position for less than twelve months. At each reporting date, we perform an evaluation of impairment to determine if the unrealized losses are other-than-temporary. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition of the issuer, and our intent and ability to hold the investment until recovery of its amortized cost basis. We intend, and have the ability, to hold our investments in unrealized loss positions until their amortized cost basis has been recovered. Based on our evaluation, we determined that the unrealized losses were not other-than-temporary as of September 30, 2017. |
Debt, Commitments and Contingen
Debt, Commitments and Contingencies | 9 Months Ended |
Sep. 30, 2017 | |
Debt Instruments [Abstract] | |
Debt, Commitments and Contingencies | 3. Debt, Commitments and Contingencies Term Loans In November 2016, we entered into a loan and security agreement (the Loan Agreement) with Silicon Valley Bank (SVB) and Solar Capital Ltd. (Solar) to borrow up to $20.0 million, issuable in three separate tranches of $10.0 million, $5.0 million and $5.0 million, respectively. The first tranche of $10.0 million was funded on November 18, 2016 (Term A Loan). Under the Term A Loan, we received cash proceeds of $7.3 million, net of a $2.6 million repayment of the principal, accrued interest and the $0.5 million final payment under our previous $10.0 million loan and security agreement with SVB (SVB Loan). We did not pay any termination or other fees in connection with the repayment of amounts due under the SVB Loan. In June 2017, we entered into an amendment of the Loan Agreement which modifies certain conditions under which we may receive and repay term loans under the Loan Agreement. The Loan Agreement, as amended, provides that (i) up to $5.0 million in the second tranche of term loans could be drawn down by us at any time before the earlier of June 30, 2017 or an event of default, at our discretion, and (ii) an additional $5.0 million in the third tranche of term loans may be drawn down by us at any time after June 30, 2017 and before the earlier of December 31, 2017 or an event of default, at our discretion, subject to achievement of certain milestones. In connection with the amendment to the Loan Agreement, the second tranche of $5.0 million was funded on June 30, 2017 (Term B Loan). We received cash proceeds of $4.9 million, net of debt issuance cost of $0.1 million. The amendment to the Loan Agreement was not a result of a troubled debt restructuring and did not result in modifications to the terms that were substantially different. Pursuant to the Loan Agreement, as amended, we were originally obligated to make interest only payments through December 1, 2017, followed by consecutive equal monthly payments of principal and interest in arrears through the maturity date of November 18, 2020. Upon achievement of certain milestones as set forth in the Loan Agreement, as amended, the interest only period was extended to June 1, 2018. The Term A Loan and Term B Loan (collectively, the Term Loans) bear interest at the prime rate, as reported in The Wall Street Journal on the last date of the month preceding the month in which interest will accrue, plus 4.10%. A final payment equal to 8.75% of the funded amounts is payable when the Term Loans become due or upon the prepayment of the respective outstanding balance. We have the option to prepay the outstanding balance of the loan in full, subject to a prepayment fee ranging from 1.0% to 3.0% depending upon when the prepayment occurs, including any non-usage fees. The Loan Agreement, as amended, provides for a 2.0% non-usage fee for any unfunded amount in the event we do not draw the third tranche, payable no later than the expiration date for the third tranche, as applicable, or the date of cancellation of the loan due to prepayment or an event of default. No such events have occurred or are anticipated as of September 30, 2017. As of September 30, 2017, the carrying value of our Term Loans consist of $15.0 million principal outstanding less the debt issuance costs of $0.7 million. The debt issuance costs have been recorded as a debt discount of long-term debt in our balance sheet, which are being accreted to interest expense over the life of the Term Loans. The final maturity payment of $1.3 million is being accrued over the life of the Term Loans through interest expense. In connection with the Term A Loan, we issued warrants to each of SVB and Solar to purchase an aggregate of 47,771 shares of our common stock with an exercise price of $3.14 per share. In connection with the Term B Loan, we issued warrants to each of SVB and Solar to purchase an aggregate of 20,833 shares of our common stock with an exercise price of $3.60 per share. The warrants are immediately exercisable and have a maximum contractual term of seven years. These warrants are included as issuance costs against the Term Loans and are amortized using the effective interest method. Future principal payments for the Term Loans and the final payment are as follows (in thousands): September 30, 2017 2017 $ — 2018 3,500 2019 6,000 2020 6,813 $ 16,313 Facility Lease In December 2011, we entered into a noncancelable operating lease that included certain tenant improvement allowances and is subject to base lease payments, which escalate over the term of the lease, additional charges for common area maintenance and other costs. In January 2017, we extended the lease for two years to May 2019. In April 2017, we amended our facility lease to include an additional 7,411 square feet through May 2019 for a total additional commitment of $0.7 million. Rent expense for the three months ended September 30, 2017 and 2016 was $0.3 million and $0.1 million, respectively. Rent expense for the nine months ended September 30, 2017 and 2016 was $0.7 million and $0.3 million, respectively. Future minimum payments under the non-cancelable operating lease as of September 30, 2017 were as follows (in thousands): Operating Lease 2017 $ 272 2018 1,108 2019 420 $ 1,800 Research Agreements and Funding Obligations (Related Party Transactions) We provide funding to The Scripps Research Institute (TSRI) pursuant to a research funding and option agreement to conduct certain research activities. We have entered into additional amendments to our research funding and option agreement in 2016 and 2017 to provide additional funding to TSRI. For the three months ended September 30, 2017, the additional funding expense recorded for TSRI was $0.3 million and zero for the three months ended September 30, 2016. For the nine months ended September 30, 2017 and 2016, the additional funding expense recorded for TSRI was $0.7 million and $0.4 million, respectively. Paul Schimmel, Ph.D., a member of our board of directors, is a board and faculty member at TSRI and such payments fund a portion of his research activities conducted at TSRI. During the three months ended September 30, 2017 and 2016, we provided no charitable contributions and $0.1 million of charitable contributions, respectively, to the National Foundation for Cancer Research. During the nine months ended September 30, 2017 and 2016, we provided charitable contributions to the National Foundation for Cancer Research of $0.2 million and $0.3 million, respectively. We have requested that the contributions be restricted to certain basic research in cancer biology and therapeutics, a portion of which funds research activities conducted at TSRI in the laboratory of Dr. Schimmel. |
Stockholders' Equity
Stockholders' Equity | 9 Months Ended |
Sep. 30, 2017 | |
Equity [Abstract] | |
Stockholders' Equity | 4. Stockholders’ Equity Private Placement of Common Stock, Convertible Preferred Shares and Common Stock Warrants On August 27, 2017, we entered into a Securities Purchase Agreement (Securities Purchase Agreement) for a private placement (Private Placement) with a select group of institutional investors, including Viking Global Opportunities Illiquid Investments Sub-Master, LP (VGO Fund) and other accredited investors, certain of whom are affiliated with our directors and officers (collectively, the Purchasers). Pursuant to the Securities Purchase Agreement, (i) VGO Fund purchased 1,777,784 shares of our common stock, par value $0.001 per share (the Common Shares), at a price of $2.65 per share, 2,285,952 shares of our Class X Convertible Preferred Stock (the Preferred Shares or Preferred Stock, and together with the Common Shares, the Shares), par value $0.001 per share, at a price of $13.25 per share, and warrants to purchase up to that number of additional shares of Common Stock equal to thirty seven and one half percent (37.5%) of the number of Shares purchased by VGO Fund on an if-converted basis (rounded up to the nearest whole share), and (ii) the remaining Purchasers purchased an aggregate of 4,094,336 shares of our Common Shares, at a price of $2.65 per share, and warrants to purchase up to that number of additional shares of Common Stock equal to thirty-seven and one half percent (37.5%) of the number of Common Shares purchased by such Purchaser (rounded up to the nearest whole share). The Private Placement closed on August 31, 2017 for gross proceeds of $45.8 million, and after giving effect to costs related to the Private Placement, net proceeds of $42.5 million. Each Preferred Share is convertible into five shares of our common stock. VGO Fund will be prohibited from converting the Preferred Shares into shares of our common stock if, as a result of such conversion, VGO Fund, together with its affiliates, would own more than 9.50% of the shares of our common stock then issued and outstanding, which percentage may change at VGO Fund’s election upon 61 days’ notice to us to (i) any other number less than or equal to 19.99% or (ii) subject to approval of our stockholders to the extent required in accordance with the NASDAQ Global Market rules, any number in excess of 19.99%. Holders of outstanding Preferred Shares are entitled to receive a dividend (on an if-converted to common stock basis), if we at any time pay a stock dividend equal to and in the same form as a dividend paid to holders of Common Shares. In the event of our liquidation, dissolution or winding up, holders of Preferred Shares will participate in any distribution of proceeds, pro rata based on the number of shares held by each such holder on an if-converted basis. The Preferred Shares have no voting rights. The warrants are exercisable at an exercise price of $4.64 per share, subject to adjustments as provided under the terms of the warrants. The warrants are immediately exercisable and expire on December 31, 2019. We also entered into a registration rights agreement (Registration Rights Agreement) with certain of the Purchasers, excluding those Purchasers affiliated with our directors and officers, requiring us to register for the resale of the relevant shares. We registered all of the relevant shares issued in the Private Placement for resale on a Form S-3 filed with the SEC, as required under the Registration Rights Agreement, and the registration statement was declared effective on September 27, 2017. Common Stock Reserved for Future Issuance Pursuant to the automatic increase provisions of our 2015 Stock Option and Incentive Plan (2015 Plan) and 2015 Employee Stock Purchase Plan (2015 ESPP), 949,793 additional shares were reserved for future issuance under the 2015 Plan on January 1, 2017 and 237,448 additional shares were reserved for future issuances under the 2015 ESPP on January 1, 2017. Common stock reserved for future issuance is as follows: September 30, 2017 Class X Preferred Stock (if-converted to common stock) 11,429,760 Common stock warrants 6,642,332 Common stock options and awards outstanding 4,745,715 Shares available under the 2015 Plan 729,139 Shares available under the 2015 ESPP 614,115 24,161,061 The following table summarizes our stock option activity under all equity incentive plans for the nine months ended September 30, 2017: Number of Outstanding Options Weighted Average Exercise Price Outstanding as of December 31, 2016 4,014,988 $ 6.73 Granted 1,041,619 $ 3.27 Exercised (32,221 ) $ 1.15 Canceled/forfeited/expired (327,971 ) $ 6.99 Outstanding as of September 30, 2017 4,696,415 $ 5.98 The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Expected term (in years) 6.06 6.02 – 6.08 5.50 – 6.08 5.50 – 6.08 Risk-free interest rate 2.1% 1.2% – 1.4% 1.9% – 2.1% 1.2% – 1.9% Expected volatility 105.9% 80.7% – 81.0% 104.0% – 124.4% 80.7% – 82.5% Expected dividend yield 0.0% 0.0% 0.0% 0.0% The following table summarizes our restricted stock unit activity under all equity incentive plans for the nine months ended September 30, 2017: Number of Outstanding Restricted Stock Units Weighted Average Grant Date Fair Value Balance as of December 31, 2016 76,713 $ 4.95 Granted 22,000 $ 3.30 Released (36,099 ) $ 4.96 Forfeited (13,314 ) $ 4.67 Balance as of September 30, 2017 49,300 $ 4.28 Stock-based Compensation The allocation of stock-based compensation for all options, including performance options with a market condition, 2015 ESPP and restricted stock units is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Research and development $ 368 $ 421 $ 1,235 $ 1,495 General and administrative 821 803 2,414 2,382 $ 1,189 $ 1,224 $ 3,649 $ 3,877 |
Organization, Business, Basis11
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2017 | |
Accounting Policies [Abstract] | |
Organization and Business | Organization and Business aTyr Pharma, Inc. (we, us, and our) was incorporated in the state of Delaware on September 8, 2005. We are focused on the discovery and clinical development of innovative medicines for patients suffering from severe rare diseases. |
Principles of Consolidation | Principles of Consolidation Our consolidated financial statements include our accounts and our 98% majority-owned subsidiary in Hong Kong, Pangu BioPharma Limited (Pangu BioPharma). All intercompany transactions and balances are eliminated in consolidation. |
Unaudited Interim Financial Information | Unaudited Interim Financial Information The accompanying interim condensed consolidated financial statements are unaudited. These unaudited interim financial statements have been prepared in accordance with United States generally accepted accounting principles (GAAP) and following the requirements of the United States Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. In our opinion, the unaudited interim financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of our financial position and our results of operations and cash flows for periods presented. These statements do not include all disclosures required by GAAP and should be read in conjunction with our financial statements and accompanying notes for the fiscal year ended December 31, 2016, contained in our Annual Report on Form 10-K filed with the SEC on March 16, 2017. The results of the interim periods are not necessarily indicative of the results expected for the full fiscal year or any other interim period or any future year or period. |
Liquidity and Financial Condition | Liquidity and Financial Condition We have incurred losses and negative cash flows from operations since our inception. As of September 30, 2017, we had an accumulated deficit of $252.7 million and we expect to continue to incur net losses for the foreseeable future. We believe that our existing cash, cash equivalents and available-for-sale investments, of $90.4 million as of September 30, 2017 will be sufficient to meet our anticipated cash requirements for at least a period of one year from the filing date of this Quarterly Report. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which we expect will take a number of years at a minimum. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, we will need to raise substantial additional capital. The amount and timing of our future funding requirements will depend on many factors, including the pace and results of our preclinical and clinical development efforts and the timing and nature of the regulatory approval process for our product candidates. We anticipate that we will seek to fund our operations through public or private equity or debt financings, collaborations, strategic partnerships or other sources. However, we may be unable to raise additional capital or enter into such other arrangements when needed on favorable terms or at all. If we are unable to obtain funding on a timely basis, we may be required to significantly curtail, delay or discontinue one or more of our research or development programs or the commercialization of any product candidates, or we may be unable to expand our operations, maintain our current organization and employee base or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition and results of operations. |
Use of Estimates | Use of Estimates Our consolidated financial statements are prepared in accordance with GAAP. The preparation of our consolidated financial statements requires us to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in our consolidated financial statements and accompanying notes. The most significant estimates in our consolidated financial statements relate to the fair value of equity issuances and awards, and clinical trials and research and development expense accruals. Although these estimates are based on our knowledge of current events and actions we may undertake in the future, actual results may ultimately differ materially from these estimates and assumptions. |
Net Loss Per Share | Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents and adjusted for the weighted average number of common shares outstanding that are subject to repurchase. We have excluded 175 and 21,871 shares subject to repurchase from the weighted average number of common shares outstanding for the three months ended September 30, 2017 and 2016, respectively. We have excluded 4,607 and 29,467 shares subject to repurchase from the weighted average number of common shares outstanding for the nine months ended September 30, 2017 and 2016, respectively. Diluted net loss per share is calculated by dividing the net loss by the weighted average number of common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for common stock, restricted stock units and options outstanding under our stock option plan and employee stock purchase plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to our net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Three and Nine Months Ended September 30, 2017 2016 Class X Convertible Preferred Stock (if-converted) 11,429,760 — Warrants for common stock 6,642,332 25,970 Common stock options and restricted stock units 4,745,715 4,356,751 Employee stock purchase plan 38,862 37,944 22,856,669 4,420,665 |
Convertible Preferred Stock | Convertible Preferred Stock We apply the relevant accounting standards to distinguish liabilities from equity when assessing the classification and measurement of preferred stock. Preferred shares subject to mandatory redemptions are considered liabilities and measured at fair value. Conditionally redeemable preferred shares are considered temporary equity. All other preferred shares are considered as stockholders’ equity. |
Derivative Financial Instruments | Derivative Financial Instruments We do not use derivative instruments to hedge exposures to cash flow, market, or foreign currency risks. We evaluate all of our financial instruments, including warrants, to determine if such instruments are derivatives or contain features that qualify as embedded derivatives. We generally use the Black-Scholes option-pricing model to value the derivative instruments at inception and subsequent valuation dates. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is re-assessed at the end of each reporting period. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities , which requires that (i) all equity investments, other than equity-method investments, in unconsolidated entities generally be measured at fair value through earnings and (ii) when the fair value option has been elected for financial liabilities, changes in fair value due to instrument-specific credit risk will be recognized separately in other comprehensive income. Additionally, ASU 2016-01 changes the disclosure requirements for financial instruments. The new standard will be effective for fiscal years beginning after December 15, 2017, and interim periods within those annual fiscal years. Early adoption is permitted for certain provisions. The adoption of ASU 2016-01 is not expected to have a material impact on our consolidated financial position or results of operations. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In May 2017, the FASB issued ASU 2017-09 , Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting, |
Organization, Business, Basis12
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Accounting Policies [Abstract] | |
Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share | Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Three and Nine Months Ended September 30, 2017 2016 Class X Convertible Preferred Stock (if-converted) 11,429,760 — Warrants for common stock 6,642,332 25,970 Common stock options and restricted stock units 4,745,715 4,356,751 Employee stock purchase plan 38,862 37,944 22,856,669 4,420,665 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Fair Value Disclosures [Abstract] | |
Schedule of Assets Measured at Fair Value on Recurring Basis | Assets measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Quoted Active for Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2017: Assets: Current: Cash equivalents $ 17,907 $ 17,907 $ — $ — Available-for-sale investments, short-term: Asset-backed securities 7,402 — 7,402 — Commercial paper 21,193 — 21,193 — Corporate debt securities 21,594 — 21,594 — United States treasury securities 10,427 10,427 — Sub-total short-term investments 60,616 10,427 50,189 — Total assets measured at fair value $ 78,523 $ 28,334 $ 50,189 $ — As of December 31, 2016: Assets: Current: Cash equivalents $ 29,251 $ 29,251 $ — $ — Available-for-sale investments, short-term: Commercial paper 7,843 — 7,843 — Corporate debt securities 20,913 — 20,913 — United States treasury securities 5,003 5,003 — — Sub-total short-term investments 33,759 5,003 28,756 — Available-for-sale investments, long-term: Asset-backed securities 4,002 — 4,002 — Sub-total long-term investments 4,002 — 4,002 — Total assets measured at fair value $ 67,012 $ 34,254 $ 32,758 $ — |
Schedule of Available-for-sale Investments | As of September 30, 2017 and December 31, 2016 available-for-sale investments are detailed as follows (in thousands): September 30, 2017 Gross Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Market Value Available-for-sale investments, short-term: Asset-backed securities $ 7,403 — (1 ) $ 7,402 Commercial paper 21,193 — — 21,193 Corporate debt securities 21,601 — (7 ) 21,594 United States treasury securities 10,433 — (6 ) 10,427 $ 60,630 $ — $ (14 ) $ 60,616 December 31, 2016 Gross Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Market Value Available-for-sale investments, short-term: Commercial paper $ 7,843 $ — $ — $ 7,843 Corporate debt securities 20,942 — (29 ) 20,913 United States Treasury securities 5,002 1 — 5,003 $ 33,787 $ 1 $ (29 ) $ 33,759 Available-for-sale investments, long-term: Asset-backed securities $ 4,001 $ 1 $ — $ 4,002 $ 4,001 $ 1 $ — $ 4,002 |
Debt, Commitments and Conting14
Debt, Commitments and Contingencies (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Debt Instruments [Abstract] | |
Schedule of Future Principal Payments for Term Loans and Final Payment | Future principal payments for the Term Loans and the final payment are as follows (in thousands): September 30, 2017 2017 $ — 2018 3,500 2019 6,000 2020 6,813 $ 16,313 |
Schedule of Future Minimum Payments under Non-cancelable Operating Lease | Future minimum payments under the non-cancelable operating lease as of September 30, 2017 were as follows (in thousands): Operating Lease 2017 $ 272 2018 1,108 2019 420 $ 1,800 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Summary of Common Stock Reserved for Future Issuance | Common stock reserved for future issuance is as follows: September 30, 2017 Class X Preferred Stock (if-converted to common stock) 11,429,760 Common stock warrants 6,642,332 Common stock options and awards outstanding 4,745,715 Shares available under the 2015 Plan 729,139 Shares available under the 2015 ESPP 614,115 24,161,061 |
Summary of Stock Option Activity | The following table summarizes our stock option activity under all equity incentive plans for the nine months ended September 30, 2017: Number of Outstanding Options Weighted Average Exercise Price Outstanding as of December 31, 2016 4,014,988 $ 6.73 Granted 1,041,619 $ 3.27 Exercised (32,221 ) $ 1.15 Canceled/forfeited/expired (327,971 ) $ 6.99 Outstanding as of September 30, 2017 4,696,415 $ 5.98 |
Schedule of Restricted Stock Unit Activity | The following table summarizes our restricted stock unit activity under all equity incentive plans for the nine months ended September 30, 2017: Number of Outstanding Restricted Stock Units Weighted Average Grant Date Fair Value Balance as of December 31, 2016 76,713 $ 4.95 Granted 22,000 $ 3.30 Released (36,099 ) $ 4.96 Forfeited (13,314 ) $ 4.67 Balance as of September 30, 2017 49,300 $ 4.28 |
Schedule of Allocation of Stock-Based Compensation for All Options Including Performance Options with Market Condition, 2015 ESPP and Restricted Stock Units | The allocation of stock-based compensation for all options, including performance options with a market condition, 2015 ESPP and restricted stock units is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Research and development $ 368 $ 421 $ 1,235 $ 1,495 General and administrative 821 803 2,414 2,382 $ 1,189 $ 1,224 $ 3,649 $ 3,877 |
Employee Stock Option [Member] | |
Summary of Assumptions Used to Determine Fair Value of Employee Stock Option Grants | The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Expected term (in years) 6.06 6.02 – 6.08 5.50 – 6.08 5.50 – 6.08 Risk-free interest rate 2.1% 1.2% – 1.4% 1.9% – 2.1% 1.2% – 1.9% Expected volatility 105.9% 80.7% – 81.0% 104.0% – 124.4% 80.7% – 82.5% Expected dividend yield 0.0% 0.0% 0.0% 0.0% |
Organization, Business, Basis16
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | |
Significant Accounting Policies [Line Items] | |||||
Accumulated deficit | $ 252,712 | $ 252,712 | $ 215,979 | ||
Cash, cash equivalents and available-for-sale investments | $ 90,400 | $ 90,400 | |||
Weighted average shares subject to repurchase | 175 | 21,871 | 4,607 | 29,467 | |
Pangu BioPharma [Member] | Hong Kong [Member] | |||||
Significant Accounting Policies [Line Items] | |||||
Majority-owned subsidiary percentage | 98.00% | 98.00% |
Organization, Business, Basis17
Organization, Business, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share (Detail) - shares | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities not included in calculation of diluted net loss per share | 22,856,669 | 4,420,665 | 22,856,669 | 4,420,665 |
Class X Convertible Preferred Stock (if-Converted) [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities not included in calculation of diluted net loss per share | 11,429,760 | 11,429,760 | ||
Warrants for Common Stock [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities not included in calculation of diluted net loss per share | 6,642,332 | 25,970 | 6,642,332 | 25,970 |
Common Stock Options And Restricted Stock Units [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities not included in calculation of diluted net loss per share | 4,745,715 | 4,356,751 | 4,745,715 | 4,356,751 |
Employee Stock Purchase Plan [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities not included in calculation of diluted net loss per share | 38,862 | 37,944 | 38,862 | 37,944 |
Fair Value Measurements - Sched
Fair Value Measurements - Schedule of Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | $ 17,907 | $ 29,251 |
Total assets measured at fair value | 78,523 | 67,012 |
Available-for-sale [Member] | Short-term Investments [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 60,616 | 33,759 |
Available-for-sale [Member] | Short-term Investments [Member] | Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 21,193 | 7,843 |
Available-for-sale [Member] | Short-term Investments [Member] | Corporate Debt Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 21,594 | 20,913 |
Available-for-sale [Member] | Short-term Investments [Member] | United States Treasury Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 10,427 | 5,003 |
Available-for-sale [Member] | Short-term Investments [Member] | Asset-backed Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 7,402 | |
Available-for-sale [Member] | Long-term Investments [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 4,002 | |
Available-for-sale [Member] | Long-term Investments [Member] | Asset-backed Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 4,002 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | 17,907 | 29,251 |
Total assets measured at fair value | 28,334 | 34,254 |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 10,427 | 5,003 |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | United States Treasury Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 10,427 | 5,003 |
Significant Other Observable Inputs (Level 2) [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Total assets measured at fair value | 50,189 | 32,758 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 50,189 | 28,756 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 21,193 | 7,843 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | Corporate Debt Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 21,594 | 20,913 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Short-term Investments [Member] | Asset-backed Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 7,402 | |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Long-term Investments [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 4,002 | |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Long-term Investments [Member] | Asset-backed Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 4,002 |
Fair Value Measurements - Sch19
Fair Value Measurements - Schedule of Available-for-sale Investments (Detail) - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016 |
Short-term Investments [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | $ 60,630 | $ 33,787 |
Gross Unrealized Gains | 1 | |
Gross Unrealized Losses | (14) | (29) |
Market Value | 60,616 | 33,759 |
Short-term Investments [Member] | Commercial Paper [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 21,193 | 7,843 |
Market Value | 21,193 | 7,843 |
Short-term Investments [Member] | Corporate Debt Securities [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 21,601 | 20,942 |
Gross Unrealized Losses | (7) | (29) |
Market Value | 21,594 | 20,913 |
Short-term Investments [Member] | United States Treasury Securities [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 10,433 | 5,002 |
Gross Unrealized Gains | 1 | |
Gross Unrealized Losses | (6) | |
Market Value | 10,427 | 5,003 |
Short-term Investments [Member] | Asset-backed Securities [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 7,403 | |
Gross Unrealized Losses | (1) | |
Market Value | $ 7,402 | |
Long-term Investments [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 4,001 | |
Gross Unrealized Gains | 1 | |
Market Value | 4,002 | |
Long-term Investments [Member] | Asset-backed Securities [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 4,001 | |
Gross Unrealized Gains | 1 | |
Market Value | $ 4,002 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) | 9 Months Ended |
Sep. 30, 2017Security | |
Schedule of Available-for-sale Securities [Line Items] | |
Available-for-sale investments in gross unrealized loss position | 18 |
Available-for-sale investments in gross unrealized loss position | 12 months |
Maximum [Member] | |
Schedule of Available-for-sale Securities [Line Items] | |
Available-for-sale investments effective maturity period | 1 year |
Debt, Commitments and Conting21
Debt, Commitments and Contingencies - Additional Information (Detail) | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended | ||||||
Jun. 30, 2017USD ($)$ / sharesshares | Apr. 30, 2017USD ($)ft² | Jan. 31, 2017 | Nov. 30, 2016USD ($)Tranche$ / sharesshares | Sep. 30, 2017USD ($) | Sep. 30, 2016USD ($) | Jun. 30, 2017USD ($)$ / sharesshares | Sep. 30, 2017USD ($) | Sep. 30, 2016USD ($) | Dec. 31, 2017USD ($) | |
Debt Instrument [Line Items] | ||||||||||
Net cash proceeds from borrowings | $ 4,930,000 | |||||||||
Loan and security agreement, payment term | The first tranche of $10.0 million was funded on November 18, 2016 (Term A Loan). Under the Term A Loan, we received cash proceeds of $7.3 million, net of a $2.6 million repayment of the principal, accrued interest and the $0.5 million final payment under our previous $10.0 million loan and security agreement with SVB (SVB Loan). We did not pay any termination or other fees in connection with the repayment of amounts due under the SVB Loan | |||||||||
Extended term of lease | 2 years | |||||||||
Noncancelable operating lease extension period | 2019-05 | 2019-05 | ||||||||
Additional lease facility | ft² | 7,411 | |||||||||
Noncancelable operating lease total additional commitment | $ 700,000 | |||||||||
Rent expense | $ 300,000 | $ 100,000 | $ 700,000 | $ 300,000 | ||||||
Research Funding and Option Agreement [Member] | The Scripps Research Institute [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Additional funding expense for research conducted | 300,000 | 0 | 700,000 | 400,000 | ||||||
Research Funding and Option Agreement [Member] | National Foundation for Cancer Research [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Charitable contributions | 0 | $ 100,000 | 200,000 | $ 300,000 | ||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | $ 20,000,000 | |||||||||
Number of tranches | Tranche | 3 | |||||||||
Term loan, debt issuance costs | 700,000 | 700,000 | ||||||||
Term loan, principal outstanding before deducting debt issuance cost | 15,000,000 | 15,000,000 | ||||||||
Final maturity payment accrued over life of term loan through interest expense | $ 1,300,000 | $ 1,300,000 | ||||||||
Warrants expiration year | 7 years | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Term A Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | $ 10,000,000 | |||||||||
Net cash proceeds from borrowings | 7,300,000 | |||||||||
Repayment of debt, principal including accrued interest | 2,600,000 | |||||||||
Debt instrument, final payment | $ 500,000 | |||||||||
Exercise price of warrant per share | $ / shares | $ 3.14 | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Term A Loan [Member] | Common Stock [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Warrants to purchase number of common stock, shares | shares | 47,771 | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Term B Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Exercise price of warrant per share | $ / shares | $ 3.60 | $ 3.60 | ||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Term B Loan [Member] | Common Stock [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Warrants to purchase number of common stock, shares | shares | 20,833 | 20,833 | ||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Tranche One [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Loan and security agreement funded date | Nov. 18, 2016 | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Tranche One [Member] | Term A Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | $ 10,000,000 | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Tranche Two [Member] | Term B Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | 5,000,000 | |||||||||
Silicon Valley Bank and Solar Capital, Ltd. [Member] | Tranche Three [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | $ 5,000,000 | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Loan and security agreement, payment term | Pursuant to the Loan Agreement, as amended, we were originally obligated to make interest only payments through December 1, 2017, followed by consecutive equal monthly payments of principal and interest in arrears through the maturity date of November 18, 2020. Upon achievement of certain milestones as set forth in the Loan Agreement, as amended, the interest only period was extended to June 1, 2018. | |||||||||
Loan amendment, description | In June 2017, we entered into an amendment of the Loan Agreement which modifies certain conditions under which we may receive and repay term loans under the Loan Agreement. The Loan Agreement, as amended, provides that (i) up to $5.0 million in the second tranche of term loans could be drawn down by us at any time before the earlier of June 30, 2017 or an event of default, at our discretion, and (ii) an additional $5.0 million in the third tranche of term loans may be drawn down by us at any time after June 30, 2017 and before the earlier of December 31, 2017 or an event of default, at our discretion, subject to achievement of certain milestones. In connection with the amendment to the Loan Agreement, the second tranche of $5.0 million was funded on June 30, 2017 (Term B Loan). We received cash proceeds of $4.9 million, net of debt issuance cost of $0.1 million. The amendment to the Loan Agreement was not a result of a troubled debt restructuring and did not result in modifications to the terms that were substantially different. | |||||||||
Maturity date | Nov. 18, 2020 | |||||||||
Percentage of funded amounts for final payment | 8.75% | |||||||||
Non-usage fee percentage | 2.00% | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Prime Rate [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Interest rate spread on variable rate | 4.10% | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Minimum [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Prepayment fee percentage | 1.00% | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Maximum [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Prepayment fee percentage | 3.00% | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Term B Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Net cash proceeds from borrowings | $ 4,900,000 | |||||||||
Term loan, debt issuance costs | 100,000 | $ 100,000 | ||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Tranche Two [Member] | Maximum [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Loan and security agreement funded date | Jun. 30, 2017 | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Tranche Two [Member] | Term B Loan [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | 5,000,000 | $ 5,000,000 | ||||||||
Current borrowing capacity under loan and security agreement | $ 5,000,000 | $ 5,000,000 | ||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Tranche Three [Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Loan and security agreement funded date, description | after June 30, 2017 and before the earlier of December 31, 2017 | |||||||||
Loan Amendment Agreement with SVB and Solar [Member] | Tranche Three [Member] | Scenario Forecast [ Member] | ||||||||||
Debt Instrument [Line Items] | ||||||||||
Available credit under loan and security agreement | $ 5,000,000 |
Debt, Commitments and Conting22
Debt, Commitments and Contingencies - Schedule of Future Principal Payments for Term Loans and Final Payment (Detail) - Silicon Valley Bank and Solar Capital, Ltd. [Member] $ in Thousands | Sep. 30, 2017USD ($) |
Debt Instrument [Line Items] | |
2,018 | $ 3,500 |
2,019 | 6,000 |
2,020 | 6,813 |
Future principal payments for term loans and final payment, total | $ 16,313 |
Debt, Commitments and Conting23
Debt, Commitments and Contingencies - Schedule of Future Minimum Payments under Non-cancelable Operating Lease (Detail) $ in Thousands | Sep. 30, 2017USD ($) |
Leases Operating [Abstract] | |
2,017 | $ 272 |
2,018 | 1,108 |
2,019 | 420 |
Operating Lease, total | $ 1,800 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands | Aug. 31, 2017USD ($) | Aug. 27, 2017Day$ / sharesshares | Sep. 30, 2017USD ($)$ / sharesshares | Jan. 01, 2017shares | Dec. 31, 2016$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Common stock, par value | $ 0.001 | $ 0.001 | |||
Preferred stock, par value | $ 0.001 | $ 0.001 | |||
Net proceeds from transaction, after giving effect to cost related to placement | $ | $ 42,487 | ||||
2015 Stock Option and Incentive Plan [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Additional number of common stock shares reserved for issuance | shares | 949,793 | ||||
2015 Employee Stock Purchase Plan [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Additional number of common stock shares reserved for issuance | shares | 237,448 | ||||
Class X Convertible Preferred Stock [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Preferred stock, shares issued | shares | 2,285,952 | 0 | |||
Securities Purchase Agreement [Member] | Private Placement [Member] | Warrants [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Exercise price of warrant per share | $ 4.64 | ||||
Warrants expiration date | Dec. 31, 2019 | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | VGO Fund [Member] | Common Stock [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Shares issued during the period | shares | 1,777,784 | ||||
Shares issued, price per share | $ 2.65 | ||||
Common stock, par value | $ 0.001 | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | VGO Fund [Member] | Warrants [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Percentage of number of shares purchased on as-converted basis | 37.50% | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | VGO Fund [Member] | Class X Convertible Preferred Stock [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Shares issued, price per share | $ 13.25 | ||||
Preferred stock, shares issued | shares | 2,285,952 | ||||
Preferred stock, par value | $ 0.001 | ||||
Convertible preferred stock, terms of conversion | Each Preferred Share is convertible into five shares of our common stock. VGO Fund will be prohibited from converting the Preferred Shares into shares of our common stock if, as a result of such conversion, VGO Fund, together with its affiliates, would own more than 9.50% of the shares of our common stock then issued and outstanding, which percentage may change at VGO Fund’s election upon 61 days’ notice to us to (i) any other number less than or equal to 19.99% or (ii) subject to approval of our stockholders to the extent required in accordance with the NASDAQ Global Market rules, any number in excess of 19.99%. | ||||
Convertible preferred stock, common stock issued upon conversion | shares | 5 | ||||
Maximum ownership percentage prohibiting conversion | 9.50% | ||||
Number of days of notice | Day | 61 | ||||
Maximum ownership percentage upon conversion, as per NASDAQ Global Market rules | 19.99% | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | Remaining Purchasers [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Gross proceeds from transaction | $ | $ 45,800 | ||||
Net proceeds from transaction, after giving effect to cost related to placement | $ | $ 42,500 | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | Remaining Purchasers [Member] | Common Stock [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Shares issued during the period | shares | 4,094,336 | ||||
Shares issued, price per share | $ 2.65 | ||||
Securities Purchase Agreement [Member] | Private Placement [Member] | Remaining Purchasers [Member] | Warrants [Member] | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Percentage of number of shares purchased on as-converted basis | 37.50% |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail) | Sep. 30, 2017shares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 24,161,061 |
Class X Preferred Stock (if-Converted to Common Stock) [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 11,429,760 |
Common Stock Warrants [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 6,642,332 |
Common Stock Options and Awards [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 4,745,715 |
Shares Available Under the 2015 Plan [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 729,139 |
Shares Available Under the 2015 ESPP [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Common stock reserved for future issuance | 614,115 |
Stockholders' Equity - Summar26
Stockholders' Equity - Summary of Stock Option Activity (Detail) | 9 Months Ended |
Sep. 30, 2017$ / sharesshares | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Number of Outstanding Options, Beginning Balance | shares | 4,014,988 |
Number of Outstanding Options, Granted | shares | 1,041,619 |
Number of Outstanding Options, Exercised | shares | (32,221) |
Number of Outstanding Options, Canceled/forfeited/expired | shares | (327,971) |
Number of Outstanding Options, Ending Balance | shares | 4,696,415 |
Weighted Average Exercise Price, Beginning Balance | $ / shares | $ 6.73 |
Weighted Average Exercise Price, Granted | $ / shares | 3.27 |
Weighted Average Exercise Price, Exercised | $ / shares | 1.15 |
Weighted Average Exercise Price, Canceled/forfeited/expired | $ / shares | 6.99 |
Weighted Average Exercise Price, Ending Balance | $ / shares | $ 5.98 |
Stockholders' Equity - Summar27
Stockholders' Equity - Summary of Assumptions Used to Determine Fair Value of Employee Stock Option Grants (Detail) - Employee Stock Option [Member] | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
Expected term (in years) | 6 years 22 days | |||
Risk-free interest rate | 2.10% | |||
Risk-free interest rate, minimum | 1.20% | 1.90% | 1.20% | |
Risk-free interest rate, maximum | 1.40% | 2.10% | 1.90% | |
Expected volatility | 105.90% | |||
Expected volatility, minimum | 80.70% | 104.00% | 80.70% | |
Expected volatility, maximum | 81.00% | 124.40% | 82.50% | |
Expected dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
Minimum [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
Expected term (in years) | 6 years 8 days | 5 years 6 months | 5 years 6 months | |
Maximum [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
Expected term (in years) | 6 years 30 days | 6 years 30 days | 6 years 30 days |
Stockholders' Equity - Schedule
Stockholders' Equity - Schedule of Restricted Stock Unit Activity (Detail) - Restricted Stock Unit [Member] | 9 Months Ended |
Sep. 30, 2017$ / sharesshares | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |
Number of Outstanding Restricted Stock Units, Beginning Balance | shares | 76,713 |
Number of Outstanding Restricted Stock Units, Granted | shares | 22,000 |
Number of Outstanding Restricted Stock Units, Released | shares | (36,099) |
Number of Outstanding Restricted Stock Units, Forfeited | shares | (13,314) |
Number of Outstanding Restricted Stock Units, Ending Balance | shares | 49,300 |
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares | $ 4.95 |
Weighted Average Grant Date Fair Value, Granted | $ / shares | 3.30 |
Weighted Average Grant Date Fair Value, Released | $ / shares | 4.96 |
Weighted Average Grant Date Fair Value, Forfeited | $ / shares | 4.67 |
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares | $ 4.28 |
Stockholders' Equity - Schedu29
Stockholders' Equity - Schedule of Allocation of Stock-Based Compensation for All Options Including Performance Options with Market Condition, 2015 ESPP and Restricted Stock Units (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | $ 1,189 | $ 1,224 | $ 3,649 | $ 3,877 |
Research and Development Expense [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | 368 | 421 | 1,235 | 1,495 |
General and Administrative Expense [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | $ 821 | $ 803 | $ 2,414 | $ 2,382 |